Allow activation of own S/MIME Certificates in iOS configuration profile (#3622)

* Update mobileconfig.php

Allow user on iOS to enable S/MIME

* Fixed indent

data/web/mobileconfig.php

@@ -95,8 +95,16 @@ echo '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
         <false/>
         <key>PreventMove</key>
         <false/>
-        <key>SMIMEEnabled</key>
-        <false/>
+        <key>SMIMESigningUserOverrideable</key>
+        <true/>
+        <key>SMIMESigningCertificateUUIDUserOverrideable</key>
+        <true/>
+        <key>SMIMEEncryptByDefaultUserOverrideable</key>
+        <true/>
+        <key>SMIMEEncryptionCertificateUUIDUserOverrideable</key>
+        <true/>
+        <key>SMIMEEnableEncryptionPerMessageSwitch</key>
+        <true/>
       </dict>
       <?php if($onlyEmailAccount === false): ?>
       <dict>